On a building job the drawings come in sets. For the people who lay pipe and pour foundations, two matter most: the drainage drawing and the foundation drawing. Both have plans and both have sections, but they answer different questions.
The drainage drawing
The drainage drawing, VA in Swedish for water and sewage, shows how the building is supplied with water and how foul water, surface water and land drainage are carried away: where the runs go, their sizes and materials, and where the chambers stand. From the plan you take the lengths of the runs and the number of chambers and bends.
The foundation drawing
The foundation drawing shows the building's foundations: strip footings, ground slab, edge units, insulation and rebar. From the plan you take lengths and areas. But how the rebar sits, and how big a footing is in cross section, is not on the plan. It is on the section.
The section
A section drawing is a cut straight through: it shows width and height, in millimetres, where the plan shows length. A foundation drawing often has several sections through different parts of the foundation, to show how the rebar lies at each point. A drainage set has a section too, showing how deep the runs lie in the ground.
- The plan gives lengths, in metres, and counts.
- The section gives width and height, in millimetres.
- Never measure a length on a section. It shows no distance on the ground.
In Mängda every document has both a kind, drainage or foundations, and a view, plan or section. On a section no tool that prices by the metre is offered, and the AI reading does not read sections: it would answer confidently and wrongly.
How they fit together
A link is the clearest example: its shape is measured on the section, but it repeats along the plan. The count therefore comes from the plan's length and the spacing, and the length of each link from the section. Take the quantities off the right drawing and they add up.